Do cancer-fighting foods exist?


According to the "2012 China Cancer Registration Annual Report" released by the China Cancer Registration Center, there are about 3.12 million new cancer cases in China every year, an average of 8,550 people every day, and 6 people are diagnosed with cancer every minute nationwide. For the country, society and every family, cancer is a huge burden. For individuals, it is the weight of life.

More and more people are paying attention to cancer, and various news and articles about anti-cancer foods have begun to be forwarded and spread by people. But are there really foods that can fight cancer?

No single food can fight cancer

We often see various claims about food anti-cancer, such as garlic anti-cancer, blueberries anti-cancer, broccoli anti-cancer, green tea anti-cancer, etc. Are there really foods that can anti-cancer? In fact, you cannot fight cancer just by eating a single food or a single food ingredient.

To verify whether a certain food may be anti-cancer, the most direct experimental method is to treat cancer cells with the food or some component it contains and observe the response of the cancer cells. Scientists call this a "cell experiment." At present, many studies have shown that many so-called anti-cancer foods do contain some special and healthful ingredients, such as vitamins, minerals, anthocyanins, flavonoids and other antioxidant ingredients in vegetables and fruits. In cell experiments, scientists found that some ingredients can delay or even inhibit the growth of cancer cells. However, this is still a long way from proving its anti-cancer effect. After all, this is just a preliminary cell experiment, which is very different from the human body.

The human body is a complex organism. The food people eat and the reactions that occur in the human body are much more complicated than cell experiments in test tubes. In addition, the food we eat is not a single ingredient but a mixture of multiple ingredients. In the laboratory, researchers often conduct experiments with purified single ingredients. For example, if people want to verify the effect of antioxidants in blueberries, they will extract antioxidants from blueberries and conduct cell experiments instead of using blueberries directly. The food in our daily life contains more than 100 ingredients at most and dozens of ingredients at least. Scientists found in cell experiments that the antioxidants extracted from blueberries are beneficial to health. However, blueberries are not only antioxidants, but also have many other nutrients. In addition, the experimental dose is also very different from the amount in people's daily diet. In experiments, scientists used large amounts of purified ingredients, but it is difficult for people to eat such doses in their daily diet. Therefore, Cancer Research UK also reminds consumers that foods or products on the market that claim to be anti-cancer are actually using "anti-cancer" as a marketing tool and have no scientific basis.

Judging from current research, a single food or food component cannot fight cancer. If you pin your anti-cancer hopes on one kind of food or a certain food ingredient, you are putting all your eggs in one basket, and they are likely to be in vain.

A varied diet can reduce cancer risk

Since it is impossible to verify the effect of a single food and a single ingredient on the human body, scientists have tried to focus their research on one type of food, such as vegetables, fruits, beans, meat and other different foods. At present, there are many population dietary surveys and studies in this area, and scientists have also reached some consensus: healthy, balanced, and diverse dietary patterns are conducive to reducing the risk of cancer. So what kind of meal can meet such standards?

The World Health Organization and the American Institute for Cancer Research analyzed the relationship between food/lifestyle and cancer based on existing data and synthesis of more than 7,000 studies, according to the strength of evidence in different studies and the degree to which a certain food/lifestyle is associated with cancer risk. risk correlations and mapped the relationship between different foods and the risk of various cancers. For example, eating leeks can reduce the risk of gastric cancer, garlic can reduce the risk of rectal cancer, non-starchy vegetables can reduce the risk of oral cancer, throat cancer, esophageal cancer, and gastric cancer, and fruits can reduce the risk of oral cancer, throat cancer, and cancer. Risk of esophageal cancer, lung cancer, and stomach cancer.

Overall, among the relationships between diet and cancer, vegetables and fruits are the most convincing in reducing cancer risk. Vegetables are rich in dietary fiber, vitamins and minerals, and are also rich in phytochemicals, such as flavonoids, organic sulfides, etc. These ingredients themselves have a good effect on reducing the risk of cancer. Dietary fiber can reduce the risk of colon cancer and esophageal cancer, and carotenoids can reduce the risk of oral cancer, throat cancer, and lung cancer.

Therefore, the mainstream opinion of major health organizations and scientific research institutions in the world believes that eating more vegetables and fruits in the diet can reduce the risk of cancer. Many organizations, including the American Association for Cancer Research and the National Institutes of Health, have launched a health program calling on people to eat 5 to 9 servings of fruits and vegetables every day, hoping to reduce the risk of cancer and promote national health. The World Health Organization also recommends eating at least 5 servings of vegetables and fruits per day (approximately 400 grams).

It should be noted that in this study, processed meat products and alcoholic beverages increased the risk of some cancers. For example, processed meat products increased the risk of colon cancer, and alcohol increased the risk of oral cancer, esophageal cancer, and breast cancer. Related The level is "definitely increased risk," and the evidence is stronger than the health benefits of vegetables and fruits. In addition, total dietary fat, animal fat, sugar, etc. also have a "limited possibility" of increasing the risk of certain cancers. Therefore, typical unhealthy meals are alcohol and various processed meat products. The way we often say "drinking alcohol and eating meat" is actually very unhealthy. From a dietary perspective, if you want to reduce the risk of cancer, you must first control the intake of the above foods.

Carcinogenesis and anti-cancer, a protracted battle

Since some studies believe that some foods can reduce the risk of cancer and some foods can increase the risk of cancer, does that mean that if you eat foods that reduce the risk of cancer every day, you will definitely stay away from cancer, and if you eat foods that increase the risk of cancer, you will definitely get it? What about cancer? The truth is far from being as simple as we imagine. Cancer is not caused overnight, and fighting cancer cannot be solved once and for all.

The occurrence of cancer is actually a risk. Since it is a risk, there must be uncertainty. Just like driving on the street, there is a risk of encountering a car accident. However, it does not mean that as long as you drive on the street, a car accident will occur. Scientists can only tell you certain ways to reduce the probability of a car accident. The relationship between diet and cancer risk also requires scientific research methods.

Generally speaking, the relationship between cancer and diet is based on studies with multiple sample sizes (large numbers of people) and long time spans, and the results of the studies are also based on statistical data with large sample sizes. The results of the study can tell us the impact of different foods on the risk of cancer, such as which foods increase the probability of cancer and which foods may reduce the probability of cancer.

Just like there are many causes of car accidents, cancer is also a disease caused by multiple factors. So far, people cannot clearly explain the cause. A certain food or dietary pattern only affects part of the risk, but does not have a decisive impact. For individuals, even if you only eat foods that are "confirmed to reduce the risk of cancer" every day, it may not guarantee that you will not get cancer in your life; even if you eat foods that are "confirmed to increase the risk of cancer," it does not mean that you will definitely develop cancer. cancer. This is the same as driving while talking on the phone is more likely to cause a car accident, but even if you never drive while talking on the phone, you may still get into a car accident due to speeding and other reasons, and you may not get into a car accident if you talk on the phone once in a while.

In addition, eating only one type of food or type of food every day is not in line with the health concept of nutrition. A healthy diet should be as balanced and diverse as possible. Eating only a single food may cause malnutrition, which is harmful to cancer. The risks will only increase. Although eating bacon once in a while and drinking beer a few times may not be good for your health, you don't have to worry too much about getting cancer. Worrying too much about food can be harmful, as stress can also increase the risk of cancer. Scientists once conducted animal experiments and conducted feeding experiments on mice exposed to radiation. They put pressure on one group of mice (someone appeared from time to time while eating). It was found that the mice in the pressure group developed tissue cancer at a faster rate. . Therefore, remember to eat in moderation when enjoying food, but don't be too worried.

Dietary recommendations for cancer prevention

It will definitely not work if you place your hopes on one food to prevent cancer, but healthy dietary patterns can still help reduce the risk of cancer. Increasing risk-reducing foods and dietary patterns in daily life, and trying to avoid foods that can increase risk, can reduce our likelihood of developing cancer and are of great benefit to our health. The American Institute for Cancer Research has summarized 10 dietary and lifestyle suggestions for cancer prevention. We might as well learn from a few dietary suggestions for cancer prevention:

  1. Try not to eat too much every day, control the balance of energy intake, try to maintain a healthy weight, and try to lose weight and stay slim as much as possible without becoming underweight.
  2. Drink less or no sugary drinks, and pay attention to eating less high-energy-density foods, such as various desserts, high-fat meat, etc.
  3. Eat a more diverse range of vegetables, fruits, whole grains and beans, preferably more than 5 types a day.
  4. Reduce the intake of meat (such as beef, pork and mutton), and try to eat less processed meat (such as sausage, ham).
  5. Try not to drink alcohol. If you need to drink alcohol, men should limit their drinking to less than 2 units of alcohol per day, and women to 1 unit of alcohol per day (1 unit of alcohol is 10 ml of pure alcohol, which is approximately equivalent to 360 ml of beer, 150 ml of dry wine or 45 ml white wine).
  6. Eat as light a diet as possible, reduce the intake of salt-rich foods or pickled foods, and control the amount of salt in the diet to no more than 6 grams per day.
  7. Do not replace food with dietary supplements. For example, don’t just take vitamin tablets instead of fruits and vegetables just because you heard that vitamin C can reduce the risk of cancer.
  8. For infants and young children, it is best to insist on exclusive breastfeeding for more than 6 months, and then gradually add complementary foods to the baby.